The present invention pertains to subsea production platforms which connect a plurality of hydrocarbon producing wells with flow lines to transport hydrocarbons to storage facilities and, more particularly, to a tool used in construction of a level platform on a monopile which is deep underwater, perhaps up to 2500 feet deep.
It is known in the art to drill a plurality of wells in the same area and to bring the product from those wells to one central point for transportion to the surface. This central point is usually a subsea structure which needs to have a nearly level platform for a template for supporting necessary associated equipment. In the prior art, a plurality of concrete pilings, leveled by adjusting the heights of the respective pilings, was used. A platform would then be secured to these pilings. However, a new system is being developed by the present assignee so as to use a single piling of quite large size, that is, of about 6 feet in diameter and a length of several hundred feet driven into the ocean floor to support a platform. A steel ring girder is attached to the monopile and it is then necessary to obtain a level surface on that ring girder in order to support a template upon which the equipment will be placed. This ring girder is normally about 25 feet in diameter and needs to be level within about 3 inches across its 25 foot diameter. As the depth increases down to more than 2000 feet, leveling of the template becomes more and more of a problem, particularly if the monopile is not nearly vertical.
Further details as to the monopile and use of a leveling wafer in connection with it may be found in assignee's copending patent applications, Ser. No. 432,880 filed Oct. 5, 1982, entitled "Method For Leveling A Subsurface Template" and Application Ser. No. 432,883 filed Oct. 5, 1982, entitled "Hydraulically Actuated Slip-Type Connector" and in Application Ser. No. 343,634, filed Sept. 28, 1982, entitled "Subsea Well Completion System", all of which are now incorporated by reference herein in their entirety.